<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    #grid {
      display: grid;
      grid-template-areas:
        "header   header  header  header"
        "leftside content content content"
        "leftside content content content"
        "footer   footer  footer  footer";
      background-color: antiquewhite;
      height: 400px;
    }

    #header {
      grid-area: header;
      background-color: blanchedalmond;
    }

    #leftside {
      grid-area: leftside;
      background-color: aqua;
    }

    #content {
      grid-area: content;
      background-color: aquamarine;
    }

    #footer {
      grid-area: footer;
      background-color: beige;
    }
  </style>
</head>
<body>
  <div id="grid">
    <div id="header">this is header</div>
    <div id="leftside">this is leftside</div>
    <div id="content">this is content</div>
    <div id="footer">this is footer</div>
  </div>
</body>
</html>